Gas production characteristics of oats and tritical silages and techniques for reducing gas emissions

Greenhouse gas (GHG) production during ensiling not only causes the nutrient losses of silage but also promotes climate warming. However, there is little information on the production of GHG and strategies for mitigating GHG emissions during ensiling. This work aimed to study the gas production characteristics and techniques for reducing gas emissions during ensiling. Oats and triticale, with Lactiplantibacillus plantarum (LP) or corn meal (CM) addition, were ensiled. The cumulative gas volume rapidly increased and reached to the peak within the first 9 d of ensiling for both forage crops. The highest cumulative gas volume of triticale silage was twice as much as that of oats silage. Triticale silage produced lower carbon dioxide (CO₂) concentration, higher methane (CH₄) and nitrous oxide (N₂O) concentrations than oats silage within the 28 d of ensiling. Adding LP or CM significantly improved the fermentation quality and decreased the gas volume and GHG concentrations of 2 silages on d 56 (except CH₄ of triticale). At the early stage of ensiling, more Enterobacter, Lactococcus and Leuconostoc related to gas production were observed, and adding LP increased the abundance of Lactobacillus and decreased the abundance of bacteria like Kosakonia, Pantoea, Enterobacter and Lactococcus positively correlated with gas volume, CO₂ and N₂O concentrations. These results suggest that gas formation during ensiling mainly occurs in the first 9 d. Adding LP or CM can significantly improve the fermentation quality and decrease the gas volume. This would benefit to reducing GHG emissions in silage production.